The present invention relates generally to a magnetic rotary encoder, and more particularly to a magnetic rotary encoder with feedback unit for monitoring operation state of a rotary motor to avoid damage or overheating of the motor.
Following the advance of science and technology, various motors have been more and more widely applied to different fields. The most often seen conventional motors can be generally divided into two types, that is, outer rotor motors and inner rotor motors. Either type of motor basically includes a hollow housing, a stator disposed in the housing and a rotor disposed in the housing and rotationally drivable by the stator. The stator is composed of multiple silicon steel plates and a coil wound on the silicon steel plates. After the motor is powered on and magnetized, the coil of the stator produces magnetic repulsion force to act on and rotate the rotor.
The stator and the rotor are both installed in the housing. Therefore, it is impossible for a user to directly observe the rotational motion of the rotor from outer side to real-time monitor whether the motor operates normally. Accordingly, if the motor abnormally operates or overheats, in a minor situation, the working efficiency of the motor will be affected and in a more serious situation, the motor may burn out and damage. In order to obviate the above problem, a magnet can be installed on the rotor of the motor and a circuit board is additionally mounted on the housing for detecting rotational motion of the magnet. When the rotor rotates, the magnet is synchronously driven and rotated. At this time, the circuit board monitors the rotational state of the rotor by way of induction. The detected signal is outward transmitted to an alarm for alerting a user of the problem. The above mechanism can be used to monitor the operation state of the motor. However, the alarm is additionally mounted on outer side of the motor. Therefore, a larger room is needed to place the alarm and the manufacturing cost is greatly increased.